Does anyone know if Benadryl has an effect on BBT? I took some last evening and this morning I had a lower BBT than expected- the lowest I've ever had! I had a BBT dip yesterday which I was hoping was an implantation dip, but with a second low day in a row, I'm crushed. Now, I did temp early as someone called me in the middle of the night and woke me from a deep sleep. When I re-temped almost 4 hours later, the temp was more like I was expecting this morning. HELP!!